Nanomaterials, such as boron nitride nanotubes (BNNT), have many potential applications in the field of electronics. However, synthesizing nanotubes with the necessary purity levels has been difficult because catalysts, such as iron, nickel and/or magnesium oxide reacted in atmospheres such as ammonia, produce undesired impurities. Before the resultant nanotubes can be effectively used, they must be purified. While most external impurities can be removed fairly easily by treating the raw product with an acid, insoluble impurities and the internal impurities are more tightly embedded and therefore, more difficult to reach without damaging the structure of the nanomaterial. Heating acid treated materials to oxidize metallic impurities and subsequently retreating in acid is known. Unfortunately, when the internal impurities oxidize, they expand causing stress and possible structural damage to the nanomaterials. Functionalization is also a known technique for removing impurities. The functionalized nanomaterial is placed in a solvent such that only the nanomaterial dissolves leaving behind the undissolved impurities. However, solvents that are completely effective are not always available. Sonification is another method used, in which ultrasonic vibration mechanically separates the impurities from the nanomaterials. This method has also been shown to cause damage to the structure of the nanomaterial.